Method of control for motor systems.



E. GRUENPELDT. METHOD OF CONTROL FOR MOTOR SYSTEMS.

Patented Feb. 23, 1909.

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APPLICATION FILED JAN.2 3, 1908.

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B. GRUENFELDT. METHOD OF CONTROL FOR MOTOR SYSTEMS.

91 APPLICATION FILED JAN. 23, 1908. Patented Feb. 23

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u M M Water/lay which I have contemplated applying pointed out in the claims.

UNITED PATENT OFFTQE.

EMIL GBUENFELDT, OF CLEVELAND, OHIO, ASSIGNOR TO THE BAKER MOTOR VEHTOLE COM- PANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

Specification oi Letters Patent. Application filed January 23, 1903.

no. 913,282. Patented Feb. as, 1909.

Serial to. 412,234.

ner indicated. SB represents a storage Dattery divided resident ture of the motor and MF the field winding of of-Cleveland, county of Cuyahoga, and State the latter. As illustrated, the field winding of Ohio, have invented a new and useful of the motor isdivided into 'four sections, the Improvement in Methods of Control for terminals of which are connected as shown. Motor Systems, of whichthe following is a In this diagrammatic view the locations of specification, the principle of the invention the contact fingers of the controller with being herein explained and the best mode in reference to each other and with reference to that the segments of the controller when the principle, so as to distinguish it from other 1 latter is in its off position, are represented inventions. by c, r, 0', d, o, e, b, c, e, d" 1), 15,1), and My invention relates to methods of con- 11. The fingers c and c are connected with trol for motor systems including a seriesthe positive and negative terminals 0 and wound motor, in which the current is C" of one of the field winding divisions, as changed from one voltage to a comparatively shown. Fingers d and d" are similarly conhigh voltage, its object being to eifect such nected with the positive and negative termichange in voltage in an economical and nals respectively of another such division. efficient manner and without sparking. Fingers e and e are similarly connected witi. The said invention consists of a method the positive and negative terminals E E" hereinafter fully described and specifically respectively of a third division, and fingers o and 0" are similarly The annexed drawings and the following, positive and negative terminals 0 and O of description set forth in detail, one mode of l the fourth division of the field winding. carrying out the invention; the disclosed Finger (1 is connected, as shown, with the mode however constituting but one of vapositive terminal of the armature, and finger rious ways in which the principle of the r is connected with one terminal R of a noninvention may be applied. inductive resistance, the other terminal R of In said annexed drawings:Figure l represents a diagrammatic view of a series which is connected with the positive termiwound motor system which may be operated Tofall whom it may concern:

Be it known that I, EMIL GRUENFELDT, a subject of the Emperor of Germany,

nal of the armature as shown. Finger 15 connected with the positive terminal B or in accordance with the principles of my 1nvention and illustrating a development of the, controller used in such. systems. Figs.

2 to 14 inclusive illustrate diagrammatically i the connections between the batteries,

motor, resistance and field-windings for the various punctuated and intermediate positicns which are occupied by the controller throughout its range of operation, for effecting the different forward speeds.

Referring to Fig. 1, S S represent the controller segments which are mounted upon a suitable insulatin cylinder in the usual manner and connector with each other by means of conductors T T in the manner indicated. These segments S are those which are used in making the connections for the forward speeds. The segments S at the upper portion of the figure are those which are utilized in making the connections for the reverse speeds andare suitably connected with each other by means of conductors T in the man-- connected with the negative terminal B or" same. Finger 1) b is connected'with the positive terminal B B of the other battery section, the negative terminal of such section being connected with the armature as shown The controller is arranged to punctuate the ositions indicated by II-III, IV-IV, V V, VI -VI, V1I--VH, V IIIVHI, IXIX, by any suitable means vsuch as the ,usual star-wheel mechanism.

It will be assumed that the battery sections are of equal capacity and that when connected in parallel they will produce 40 volts and when in series, volts. Let it now be assumed that the controller is moved so as to bring the contact fingers c, 0', etc. with reference to the segments of the con troller, into the position indicated by line l-I. In this osition the connections are those illustrate that the field winding sections are in series into two sections, MA the arms.

connected with the one of the battery sections and finger if is in Fig. 2, and it will be noted the circuit. the )OSltlOIl indicated 1) line V V the lield with the resistance and that the battery sections are in parallel. Therefore we have the highest resistance which the circuit can present and the lowest voltage, thereby obtaining the lowest speed of the motor. now be assumed that the next stop of the controller will bring the fingers upon the line llll. In. this position the connections are those illustrated in Fig. 0, and it will be noted that the resistance has been cut out of circuit, but that otherwise the connecn remain as in the position described in the first or lmvest speed. The segments are so arranged that the next step of the coner will bring the fin ers upon the line ill. in this position the field sections connec ed in series parallel as illustrated in Fig. 4, t remaining connections remaining as descr z ed when the motor is on 2d speed. This last named position gives a 3d speed higher than the 2d. On the 4th speed, the connections are as described in connectionwith the 3d speed w th the exception that the resistance is shunted so as to increase the amount of current passing dir'ec'tl from the battery to the armature as shown in Fig. Such arrangement gives us the 4th and an increased speed, the position of the fingers being indicated by line IV1V. l/Vhen the controller is next shifted so as to bring the fingers upon the line.

V-V, the connections are such as to cut out the resistance and arrange the field sections in parallel, the other connections remaining as'in speed 3, as shown in Fig. 4.

The position of the fingers with reference to the controller segments for the 6th speed indicated by line Vl-V I in which it will be noted that connections are such as to place the field windings in series and the batteries also in series as diagrammatically shown in Fi 11, in which position the batteries give a current of volts. Before the fingers reach the position in which the vol tage is changed from low to high, they assume a series of intermediate positions, the connections for which are diagrammatically illustrated in Figs. 7, S, 9 and 10, and which I shall now describe. When the fingers reach the position indicated by line V -V, it will be noted that the segment S is engaged by finger 1-. Immediately thereafter the initial steps in changing the field connections from parallel to the series relation as shown in vidig. 7, takes place, the entire current being sent through one field section at one period in the change and before the completion of such connection so as not to create a break in the circuit. A further movement now breaks the connection with the armature segment, thereby placing the resistance in By the time the fingers reach sections are connected in series as shown in said Fig. 7 and the resistance 1S also in series Let it therewith in addition.

- with such sections, as illustrated in Fig. 8, the

low voltage battery connections being, however, maintained throughout. such chan es. It will be noted that the connections ast described are identical with the connections which were established for the first or lowest speed, as illustrated in Fig. 2, in which the highest resistance was established in the circuit by connecting the field windings in series and introducing the resistance in series A further movement of the controller to impart to the fingers the position indicated by line .V' V, breaks the battery connections, the field winding, armature and resistance connections remaining as just described. This last arrangement of the connections is illustrated in Fig. 9. A further movement of the controller now brings the fingers into the position indicated by line V V, in which the battery connections are reestablished, but instead of be ing in parallel are now in series, as illustrated in 'Fig. 10, and are therefore arranged for maximum voltage. A further movement of the controller new brings the fingers into the punctuated position indicated by line Vl- VI, the connections of which are illus trated in Fig. 11. At the instant the high voltage connections are made, in the positions above described and intermediate of the 5th and 6th speeds, the circuit is therefore arranged for maximum resistance and the amount of current which is therefore permitted to pass through the circuit is re-- duced to a minimum, thus also reducing the sparking incident to such change to a minimum. The resistance of" the circuit is arranged so that when the connections are made for the 6th speed as described, the reduction in amperage of the current will be substantially in the same proportion as the increase in voltage which takes place as a result of throwing the two batteries into series with each other. The wattage con sumpt'ion therefore on the 5th speed will be substantially equal to that on the 6th speed. Substantially the same speed is therefo re obtained from the 6th position, illustrated in Fig. 10, as is obtained from the 5th, that is after changing from low to high voltage.

The wattage consumption of the apparatus when the controller occupies its 5th position being substantially the same as that of the parts when the controller occupies the 6th position and the speeds resulting from these two changes being substantially the same as above described, it will therefore be seen that by making the change from 5th to 6th 7 positions quickly the momentum of the rotat ing parts which was obtained on 5th speed will not be caused to decrease before the con- .nections for the 6th speed are made and after the 5th speed connections have been broken. This means that there will be practically no current consumed during such ing as would erasestransition and t" atjthcretore the sparking will be exceding ly small at the in stant of breaking the low voltage battery connections and otr'na'king the high voltage battery connections. The proper movement for eii'ectingwho intermediate posi-- tions illustrated in-Figs 7','- 8, 9 and 10 is obtained by arranging the mechanical details of the controller so that the travelof the. con-. troller between the positions for 5th-and (5th speeds is un unctuated'and hence continuous, as will e-understood, and as explained in my oo-pen ling applioati a, Serial No. 412,235, file even date herewith.

The resistance of the field windings is madesuches to'eifect the above result, but to still further reduce even such slight sparkbe obtained, the resistance is also introducedinto the circuit in series as previously described before the low voltage connections are broken and the high voltage battery connections are made. immediately after the high voltage connections are made, the resistance is cut out and-we have the same field-winding and armature connec'-' ticns for the 6th speed'as were obtained on the'Zd speed. By so cutting out theresistance after efiecting the connections described, loss of current due to continued use of resistance is eliminated at the same time making it possible to obtain a gradual increase otnp'eed. A further step of the controller to brin 'theoontactfinger into the celtion indicatec by lines VIP-VILVIll- 111 and IXlX efiect changes in the connections identical with those explained in connection with the 3d, lth and 5th speeds in so far as concern the field armature and resistance The connections for these last three positions are illustrated in Figs. 12, 13 and 14. Three additional speeds are thereby obtained.

In the arrangement illustrated, the segmcnts S S are arranged to eilect reverse connections identical with those made for the 1st, 2d and 3d speeds forward, and the seg ments and their connections are arranged accordingly as will be readily understood.

The segments are so arranged as to accomnlish the changes in field connections without breaking the current, by passing the latter during the changes through one part of the field. This is accomplished as heretofore by arranging the intervals between the alined segments as illustrated, wherein certain of such intervals are of alength such that the corresponding fingers may contact two successive segments at the same time. The longer intervals are filled with suitable insulating material as shown to bring them ilush with the segments.

1 therefore particularly point out and dis tinntl'y claim as my invention:

1. The method of control for motor sysamount of i terns HlGllldlDgiESQZlBS wound motor lnwhich the current is changed from one voltage to a comparatively lughivoltage, whichgconsists in reducing the amperage in stantially-the same proportion as the voltage is increased and making the connections which will effect such result before thelow voltage connections are broken, then making the high voltage connections. i I 2. The method of control for a motor sys- 1 tern including a series-wound motor in which g the current is changed from one voltage to a l comparatively high voltage, which consists in increasing windings, introducing a resistance in series with such windings, breaking the low voltage connections and then making the high voltage connections While the resistance is still in series. 5

3. The method tern including a series-wound motor in whlch I the current is changed from one voltage to a comparatively high voltage, which consists in changing the connection of the motor fieldwindings to produce a comparatively high resistance, breaking the low voltage connections and then making the high voltage connections while such windings are arrange for such high resistance. 3 l i. The method of control for motor sysf including a series-wound motor in which the current is changed from one voltage to a comparatively high voltage, which consists in changing the resistance of the motor fieldwindings from the minimum to the maximum, breaking the low voltage connections and then making the high voltage connections while such windings are arranged for maximum resistance. 5. The method of control for motor sys 1 tems including a series-wound motor inwhich the current is changed from one voltage to a comparatively high voltage, which'consists in changing the field-windin s from a paral l;

lel to a series relation, breaking the low vol,-

voltage connections while such windings are l arranged in series.

l 6. The method of control for motor systerns including a series-wound motor in which i the current is changedfrom one voltage toa l comparatively high voltage, which consists in increasing the resistance of the motor fieldl windings therefor, introducing resistance into the circuit in series with such windings, breaking the low-voltage connections, making the high voltage connections while the re-- sistance is still in series, and then cutting out such resistance.

7. The method of control for motor syse toms including a series-wound motor which co -:sists in reducing the amperage in the circuit below what it will be after the change l to high voltage has been completed before the circuit in sub the resistance of the motor fieldof control for a motor sys tage connections and then making the high.

the low Voltage connections have been broken and maintaining such low amperage until the high Voltage connections have been made; then increasing the amperage so as to make the ultimate decrease in amperage substantially proportionate to the increase in voltage.

Signed by me, this 21st day of January,

Atte

A. E. BEiERKEL. 

